The invention relates to a single-track engine-driven motor vehicle having a frame support structure for receiving at least one engine in a fastening manner, wherein the frame support structure includes supporting cladding parts.
Load-bearing bodies are known from the prior art. In particular, in the case of relatively old scooters, their bodies even act as a chassis themselves. Body shapes of this type are unsuitable, however, for current motorcycles or scooters, since they do not have a sufficient stiffness and their handling is service-unfriendly in the case of repairs. For this reason, a change has been made, such as installing a frame as a load-bearing structure, to which, for example, the engine is fastened. In addition, fairing parts are attached to the frame for the design and/or aerodynamic improvement purposes. The known fairing parts do not contribute to the stiffness of the body or the frame construction, however. Rather, the various frame and fairing components and the assemblies compete for the installation space which is greatly restricted in motorcycles and scooters. The frame itself is always fixed, however, and restricts the accessibility to assemblies such as engine, transmission, etc. in the case of servicing. In addition, the frame is usually manufactured from steel and is therefore weight-intensive.
The invention is therefore based on the object of providing a motor vehicle with a frame support structure which is lighter, ensures more installation space for further components and, in the case of servicing, provides improved accessibility without significantly impairing the stiffness of the frame support structure.
This and other objects are achieved in accordance with embodiments of the invention. It is provided here according to the invention to form the frame support structure for receiving at least one engine of a motor vehicle, in particular a motorcycle or scooter, in a fastening manner from frame elements and at least one supporting cladding part made of fiber reinforced plastic. The overall stiffness of the frame support structure is determined by the at least one supporting cladding part.
It is provided in one advantageous embodiment that the at least one supporting cladding part is formed from Carbon Fiber Reinforced Plastic (CFRP). Here, a sandwich construction, in particular, is favorable, in the case of which an upper layer and a lower layer made from CFRP are connected to a spacer element which lies in-between, for example in the form of a polyurethane layer. As an alternative solution, it is possible to provide a honeycomb structure which, as is known, ensures a high stiffness along the honeycomb direction.
From the aspect of an economical and cost-optimized solution, it is favorable that the at least one supporting cladding part is formed from recycled CFRP molded material. Recycled CFRP molded material of this type can also be used in a sandwich construction as an upper and lower layer, as described above.
It is provided in a likewise advantageous design variant that the at least one supporting cladding part is configured as a cladding segment and stiffens flat sections of the frame support structure. In one embodiment as a cladding segment, the supporting cladding part can replace existing frame elements. One application is particularly suitable, for example, in the case of which a frame stiffening strut in the front part of the frame support structure is replaced by way of a supporting cladding part or a cladding segment.
The stiffness and therefore the load-bearing effect of the supporting cladding parts can be improved further if they are of multiple-walled configuration. It is provided here in one solution that the multiple-walled supporting cladding part has at least one flow-through opening, onto and/or through which flow can pass during driving in the installed state. Therefore, an aerodynamic effect by way of the supporting cladding part which also defines the frame support structure can assume additional tasks, by way of which the driving behavior can be influenced or assemblies can be cooled, for example, while driving at high speed. Furthermore, it is provided for the latter in one design variant that the supporting cladding part has through-holes at least in sections, and the through-holes extend through at least one wall in the case of a multiple-walled configuration, with the result that the air which flows through has a cooling action. In one particular embodiment, two walls of the multiple-walled construction form a nozzle, within which the pressure drops during the flowing through (Bernoulli equation). In the case of a simultaneous arrangement of the through-holes within the nozzle, the negative pressure can be used to extract hot air, for example.
In a further advantageous design variant, a heat protection foil which makes mounting close to the engine possible is arranged on the at least one supporting cladding part.
Furthermore, an exemplary embodiment is favorable, in which the at least one supporting cladding part is configured in two parts and can be assembled, with the result that mounting and dismantling it from two sides is ensured.
The invention comprises various arrangements of the supporting cladding part. It is favorable, however, in the case of a motorcycle that the frame support structure is configured so as to enclose the engine, the frame elements defining an upper driver-side section, a section which points toward a front wheel and a section which points toward a rear wheel, and the at least one supporting cladding part defining a lower section which points toward the roadway. This is precisely the other way around in the case of a motor scooter which requires a step-through for legs. Here, the frame support structure is configured so as to enclose the engine, the frame elements defining a lower section which points toward the roadway, a section which points toward a front wheel and a section which points toward a rear wheel, and the at least one supporting cladding part defining a driver-side section.
Further advantageous developments of the invention are characterized in the sub-claims and/or will be shown in greater detail in the following text together with the description of the preferred embodiment of the invention using the figures, in which, by way of example and diagrammatically.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.